Fundamentals of multiple plane stereo particle image velocimetry

For complex flow analysis in air, a stereoscopic particle image velocimetry-based system was developed, tested and applied which allows the determination of all three velocity components in spatially separated planes simultaneously (in order to determine the vorticity vector field for example) or separated in time (for space-time investigations). For this purpose, the flow field was illuminated with orthogonally linearly polarized light delivered by four frequency doubled Nd:YAG lasers. The light scattered by the tracer particles was separated by means of a polarizing beam-splitter pair onto the sensors of four progressive-scan CCD cameras in an angular imaging configuration with Scheimpflug correction.